Sheet metal governor weight



June 9, 1931'. o. wuL-FERT 1,809,

- SHEET METAL eovmwon WEIGHT Filed April 28, 1930 Invenj: or

Atty.

Patented June 9, 1931 UNITED STATES PATENT OFFICE OTTO WULFERT, OF ST. LOUIS, MISSOURI, ASSIGNOR TO WAGNER ELECTRIC CORPORA- TION, OF ST. LOUIS, LIISSOUBI, A CORPORATION OF DELAWARE SHEET METAL GOVERNOR WEIGHT Application filed April 28,

In certain types of electric motors the circuits of the machine are modified when it reaches a predetermined speed to change its characteristics into those more suitable for running conditions; One means of securing such modification of the motor circuits is by the use of a centrifugal governor driven from, and usually mounted directly on, the rotor shaft, the movement of such governor being communicated to switch devices controlling certain of the motor circuits.

Centrifugal governors, for the purpose above set forth, are of two types. First, those in which thegovernor weights move in a plane at right angles to the axis of their driving shaft, and second, those in which the weights move from a position in which they extend along the shaft toward a position at right angles thereto.

Governors of the first named type have the advantage that the weights, owing to their flat form, may be readily stamped from sheet metal, thus securing uniformity of weight and shape. They, however, have the disadvantage that the movement of their weight in a plane at right angles to the shaft must be converted by link or cam mechanism into movement in the direction of the length of the shaft. In governors of the. second 0 named type the weights bear directly against the control rods, which are parallel with the shaft, thus obviating the use of link or cam motion converting mechanism. Owing to their necessarily complicated shape they have heretofore been made of cast metal, re.- sulting in a certain amount of variation in both their shape and mass with consequent lack of uniformity in operation of machines intended to be identical.

The object of my invention is to provide a form of governor weight and method of manufacturing the same by means of which governors of the second named type may have the uniformity and accuracy of action heretofore secured only by those of the first named type. This I accomplish by forming weights, adapted for use in the second named type of governors, from sheet metal by stamping and bending operations as will be hereinafter set forth.

1930. Serial No. 447,883.

In the accompanying drawings, which illustrate one form of governor weight made in accordance with my invention, Figure 1 is a sectional view of a portion of an electric motor to which the governor is applied;

Figure 2 is a section taken on the line 22 of Figure 1, showing the weights in partially extendedposition; Figure .3 is a view of one of the weights looking from the opposite side; Figure 4 is a section taken on the line H of Figure 2, but showing the weights in a more extended position; and Figure 5 is a plan View of a blank for forming one of the weights.

Referring first to Figure 1 of the drawings, 1 indicates the frame of an electric motor provided with a field magnet 2 and an armature 3, the latter being mounted on a shaft 4 and provided with passages parallel with the shaft for the reception of push rods 5, the. movement of which controls the switching mechanism (not shown) by means of which the circuits of the motor are modified when it has reached a predetermined speed. The ends of the rods 5, which ends are preferably hemispherical in form, contactwith, a pair of governor elements 6 mounted on a pivot pin 7 extending through the shaft 4; at right angles to its axis. These elements are each so shaped as to straddle the shaft when the motor is at rest, as shown in Figure 1, thus bringing the center of gravity of each element closeto the axis of the shaft, resulting in a quick or snappy action when the armature has reached the predetermined speed of rotation.

Each governor element is formed from a stamped out blank of sheet metal of the form shown in Figure 5, comprising, in addition to the body part 6, a pair of similar wings 8, a pair of pivot lugs 9, and a contact lug 10. On each wing are three strips or fingers 11, 12 and 13, respectively, the central strip 12 of each set being preferably somewhat longer than the side strips 11 and 13. The center point of the contact lug 10 is situated slightly at one side of a line A--A extending centrally betweenthe two lugs 9 and the two wings v8, and the wing at that side of the line is positioned slightly furtheralong a line CC,

in the direction indicated by the arrow head on this line, than the other wing is along a corresponding line DD, the measurement in both instances being from a line BB perpendicular to the line A-A. The amount of this displacement of the center of the lug 10 with respect to the line AA, and of one of the wings with respect to the line B-B, depends upon the thickness of the metal from which the blank is'formed, being'slightly greater than one-half of such thickness and is for the purpose of securing symmetrical positioning of the pair of weights on the shaft, as will be hereinafter set forth. Each blank is provided, preferably when stamped out, with a pair of pivot openings 15 in the lugs 9 for engagement with the pin 7, and with a recess 14 in the lug 10 for engagement with one of-the push rods 5.

In forming a weight from the blank the strips 11, 12 and 13 are first folded over against the wings 8 and the edges of the wings folded over at right angles to the first folds to form a triangular weight member having portion shaped to straddle a shaft, and a pair of wings projecting laterally from the body part, said wings being formed by folding said strips against the blank and folding the blank to enclose the strips within the wings to produce weight members.

In testimony whereof, I hereunto aflix my signature, this 23d day of April, 1930. r e OTTO WULFERT.

the strips as a core or filler and consequently approximating the mass of a solid body of similar shape and dimensions. The body 6 of the blank is now bent into U-shape, the lug 10 bent down at right angles to the body, and the weight members 8 bent outwardly to project in opposite directions at right angles from the body. All these bending operations are performed by suitable bending dies to secure uniformity of shape in the resulting weights.

In order that two governor elements of exactly the same shape may be used to form the complete governor, one of the lugs 9 of each element must be separated from the shaft 1 by one of the lugs of the other element, as shown in Figure 2. This would result in the displacement of one element toward the i right hand side of Figure 2 a distance equal to one-half the thickness of the lug, and the other an equal distance toward the left hand side, except for the fact that this displacement is neutralized by the asymmetrical position of the lug and wings in the blank above described.

The governor elements being formed from stamped blanks of uniform thickness and the shaping being performed uniformly by bending dies, the result is that the governor elements may not only be cheaply manufactured but are uniform in both mass and shape, and governors formed from them will consequently operate accurately at the predetermined speed of rotation.

Iaving fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A governor element formed from a punched sheet metal blank having integral strips, said element having a weight member produced by folding said strips against the 

